Lecture 36: Evolution of the nervous system 2

Question 1

Name 3 phylum?

Answer 1

porifera
cnidaria
mollusca

Question 2

whats an example of a Porifera?

Answer 2

sponges

Question 3

Do Porifera have neurones?

Answer 3

no

Question 4

whats the sensory structure of the Porifera?

Answer 4

reactive ectoplasm

Question 5

what an example a cnidaria and the neural organisation?

Answer 5

jellyfish and anemones

diffuse nerve net

Question 6

whats an example of a Platyhelminthesand its neural organisation?

Answer 6

flatworm

Cerebral ganglia, longitudinal nerve cords, transverse connectors

Question 7

which three phylum have a sensory structure known as ocelli?

Answer 7

Cnidaria
Platyhelminthes
Annelida

Question 8

whats na example of a Mollusca?

Answer 8

Snails, slugs, squid

Question 9

whats the neural organisation of a Mollusca?

Answer 9

Cephalic ring of several major ganglia and nerves

Question 10

whats the sensory structure of a Mollusca involve?

Answer 10

Complex eyes, statocysts, chemo, olfactory and tactile receptors

Question 11

what type of phylum are,

Insects, spiders, crustacea ?

Answer 11

Arthropoda

Question 12

whats the neural organisation of Arthropoda

?

Answer 12

Cerebral ganglia, double ventral nerve cord and segmental ganglia

Question 13

whats the sensory structure of anthropoda?

Answer 13

Compound eyes, mechano, chemo and olfactory receptors

Question 14

Name 2 examples of Echnodermata

Answer 14

Starfish, sea urchins

Question 15

hat neural organisation do Echnodermata have?

Answer 15

Nerve ring, radial nerves, subdermal plexus

Question 16

sensory structures of Echnodermata

are?

Answer 16

Eyespots, epidermal sensory cells

Question 17

what san example of chordata?

Answer 17

Vertebrates

Question 18

whats the neural organisation of chordata?

Answer 18

Dorsal tubular brain and spinal cord, cranial, spinal and autonomic nerves

Question 19

whats the sensory structures that Chordata have?

Answer 19

Special sense organs (hearing, vision, taste, smell, lateral line),

Question 20

Spinal nerves are _______ like annelids

Answer 20

segmental

Question 21

where is the nerve cord in a rat?

Answer 21

dorsal

Question 22

where is a nerve cord in annelids and insects?

Answer 22

ventral

Question 23

the beginning of the vertebrate nervous system started with?

Answer 23

Tunicate tadpoles

Question 24

whats needed for a vertebrate nervous system?

Answer 24

Brain
Dorsal nerve cord
Notochord (developmental)
Pharyingeal slits (developmental)
Post-anal tail (developmental)

Question 25

what stem difference between a ganglion and a Brain?

Answer 25

(1) a brain subserves the entire body, not just restricted segments;
(2) it has functionally specialized parts;
(3) it is bilobar;
(4) commissures and neurons form the surface with axons in the central core;
(5) interneurons are more numerous than primary motor or primary sensory neurons;
(6) multisynaptic rather than monosynaptic circuits predominate.

Question 26

whats the NS of a roundworm like?

Answer 26

unsegmented nematode (ascaris) with dorsal and ventral nerve cords

Question 27

whats the NS of a ribbon worm like?

Answer 27

nemertean with one dorsal and two ventral nerve cords and a cerebral ganglion

Question 28

whats the NS of a leech like?

Answer 28

annelid (segmented) with cerebral ganglia and ventral nerve cord

Question 29

whats the NS of a acorn worm like?

Answer 29

acorn worm (balanoglossus) a hemichordate with dorsal and ventral nerve cords

Question 30

whats the NS of a amphioxus like?

Answer 30

a cephalochordate with dorsal nerve chord and notochord

Question 31

where is the nerve cord located on a planarian?

Answer 31

lower centre section of the parenchyma

Question 32

where is the nerve cord located on a nematode?

Answer 32

top and bottom centre

Question 33

Tunicates have a _____ in the tadpole stage

Answer 33

notochord

Question 34

whats the structure of a amphioxus?

Answer 34

Amphioxus has several chordate features
Dorsal nerve cord
Notochord 
Pharyngeal slits
Myomeres
Post-anal tail

Question 35

Amphioxus nervous system has potentially _____ regions

Answer 35

homologous

Question 36

what are some evolutionary trends?

Answer 36

• Increase in complexity
• New circuits added to old ones (layering)
• increase in size
• Absolute Vs relative

Question 37

whats the jawless fish?

Answer 37

Myxine (hagfish)